1. Field of the Invention
The present invention relates to a full-color organic light emitting diode display device and a method of fabricating the same.
2. Description of the Related Art
In general, an organic light emitting diode display device is a light emitting diode display device in which electrons and holes are injected into a light emitting layer from an electron injection electrode (a cathode) and a hole injection electrode (an anode), respectively, and light is emitted when excitons produced by combining the injected electrons and holes make a transition from an excited state to a ground state.
Therefore, unlike a conventional liquid crystal display device, a separate light source is not required in the organic light emitting diode display device. As such, the organic light emitting diode display device can be made to be relatively small in volume and light in weight.
The organic light emitting diode display device may be divided into a passive matrix type and an active matrix type according to its driving method.
The passive matrix organic light emitting diode display device has a simple structure, and thus, its fabrication method is also simple. However, it has high power consumption, and it is difficult to realize a large size. Also, as the number of interconnections increases, an aperture ratio may be lowered.
Therefore, the passive matrix organic light emitting diode display device is typically utilized as a small-sized display device. On the other hand, the active matrix organic light emitting diode display device is typically utilized as a large-sized display device.
The organic light emitting diode display device may have a bottom emission structure or a top emission structure depending on a direction in which light generated from a light emitting layer is emitted. In the bottom emission structure, light is emitted toward a substrate (or a base substrate). A reflection electrode or reflection layer is formed as an upper electrode, and a transparent electrode is formed as a lower electrode. In the case that the organic light emitting diode display device employs the active matrix type in which a thin film transistor is formed, light is not transmitted through a portion at which the thin film transistor is formed, and thus, an area through which light is emitted may be reduced. By contrast, in the top emission structure, a transparent electrode is formed as the upper electrode, and a reflection electrode or reflection layer is formed as the lower electrode, so that light is emitted in a direction away from the substrate (or the base substrate). For this reason, an area through which light is transmitted may be increased, and thus, luminance may be improved.
Also, in a full-color light emitting diode display device having red, green and blue pixel regions formed on a first electrode of a substrate, an afterimage life-span in the red pixel region is relatively shorter than that in the green and blue pixel regions. Therefore, it is difficult to reproduce full colors.